Device-to-device, D2D, communications over social channels, e.g. as an underlay to cellular networks, have been proposed as a means to take advantage of the proximity of communicating devices. Recently, there has been a rise in the use of radio technologies to provide a distribution medium between devices in the same neighborhood. Neighbor Awareness Networking (NAN) is a wireless personal area network technology designed by Wi-Fi Alliance to provide wireless connectivity over so-called social channels. In such a setting, devices may scan the social channels to discover other user devices or wireless access points (APs) with which to synchronize. NAN (aka Wi-Fi Aware) enables power efficient discovery of nearby information (devices, people, access points) and services (with always-on Wi-Fi), using device-to-device communication. Devices that want to communicate directly, or even just discover each other, typically need to transmit various forms of control signaling. One example of such direct control signaling is a so-called discovery signal, also known as a beacon signal, which at least carries some form of identity and is transmitted by a device that wants to be discoverable by other devices. Other devices can scan for the beacon signal. Once the devices have detected the beacon, they can take the appropriate action, for example, to try to initiate a connection setup with the device transmitting the beacon. NAN will make it easy to find services available in the area that match preferences set by the user—and is optimized to work well even in crowded environments. A large number of NAN devices is expected to be out in the market by the end of 2015. More details can be found at http://www.wi-fi.org/discover-wi-fi/wi-fi-aware and https://www.wi-fi.org/file/neighbor-awareness-networking-technical-specification-v10-0 (Section 1 and 2 covers Introduction and Architecture of NAN).
NAN device is defined as a mobile handset/laptop or any other communication device certified by the Wi-Fi Alliance Wi-Fi Aware program. The communication between NAN devices is based on the 802.11n physical layer, which operates at 2.4 GHz and 5 GHz carrier frequencies. The NAN specification defines new MAC mechanisms to support the cluster formation, master selection within a cluster, cluster discovery and acquiring synchronization within a cluster, cluster selection and merging, NAN service discovery protocol, etc. The NAN protocol supports the formation of a cluster and maintaining time synchronization within the cluster based on transmissions of NAN synchronization beacons. A NAN master device transmits NAN discovery beacons to announce the existence of the cluster to the neighbors, who are not part of NAN cluster. A NAN device transmits NAN-related signals. Recently, there has been a rise in the use of radio technologies, such as IEEE 802.11 and 3GPP LTE, to provide a distribution medium between devices in the same neighborhood.
Devices with fixed MAC addresses can be detected and tracked. The tracking can correlate location information and other performances to accurately identify the user, the user's friends, and his favorite applications. The building of social networks or social relations among people who, for example, offer services, share interests, contacts, activities, backgrounds, or real-life connections is expected to grow with the D2D communication. For such networking, each user has to reveal his/her profile (service offering) to the nearby devices to be linked to them. User identities are to be protected according to legal requirements and/or the involved use case, such as where NAN is being used by members of a presidential campaign team.
NAN specification (release 1) provides some privacy by the support of local NAN Interface Addresses, which may be occasionally changed. There is a need to support data transfer capability along with the existing capability to publish/subscribe to the services in more privacy protected and secure manner. Furthermore, there is a need to avoid user profiling based on service identity, ID, transmission in NAN service discovery frames. Service identity list attribute is transmitted by the STAs as a part of NAN Synchronization and Discovery beacons, which consists of a list of services being offered by the cluster in the form of a hash value of the service name/identifier, i.e., a service identity. Also STAs within the cluster transmit NAN service discovery frames which carry a service descriptor attribute consisting of service identifier; service identity/service ID is hash of service name, service information that depends on application and not specified in the specification, service control field that indicates if the Service Descriptor attribute corresponds to Publish, Subscribe, or Follow-up function and if other optional fields are present in the Service Descriptor attribute such as Matching Filter, Service Response Filter, and Service specific information.
One problem related to preserving privacy between two users sharing personal information is to allow sharing of personal information only if there is a matching of the common information between the two users.
However, there is a general need in the state-of-the-art of D2D networking, e.g. social networking, to avoid user profiling to protect privacy i.e. preventing a malicious entity (e.g. application, station, user equipment) to form a list of stations providing the specific service and/or a list of stations subscribed to the specific service. Such user information profiling may be against the privacy laws and also may be used for targeting profile based advertisements.